Attrition mill



Aug. 13', 1929. A. SCHUCHARDT 1,724,318

AI'TRITION MILL Filed June 18, 1928 4 sheetssneet 1 u/f/r/l/f/JMINVENTOR.

ATTORNEY. A

Aug. 13, 1929. A. scHucHARDT l1,724,318

ATTRITION MILL Filed June 18; 1928 4 Sheets-Sheet 2 JNVENTOR,

A TTORNE Y.

Aug. '13," 1929.

A, SCHUCHARDT ATTRITION MILL Filed June 18,v 1928 4 Sheets-5heet 3INVENTOR.

A TTORNE Y.

Aug. 13, 1929. A. scHucHARDT ATTRITI ON MILL Filed June 1s, 1928 4sheets-sheet 4 INVENTOR,

By z//dw A TTORNEY.

Patented l, i929..

.TATES lli AUGUST SCHCHARDT, OF WINONA, MINNESOTA..

ATTRIIIUN MILL.

Application filed June 18, 1928. Serial No. 286,170.

rlhe invention relates to attrition mills and more especially to thattype known under the name ot double head attrition mills.

rlhe object ot' the invent-ion is to provide a mill ot the classindicated, the pedestals whereof are cast integrally with the base.

A further object of the invention is to provide an attrition mill, thetwo centrally located pedestals whereofv 'are cast integrally with thelower casing, so that said two pedestals are rigidly connected with eachother by means of the walls of the lowerl casing whereby this centralportion ot the base will be greatly strengthened.

Another object of the invention is to provide an attrition mill thepedestals whereof are olf such height, that the upper edge thereofapproximately. coincides with the axes ol" the milling shafts, so thatthe bearings will be supported in the manner ot hanging bearings and notof standing bearings.

A still further object ol' the invention is to provide an attritionmill, the pedestals whereof are cast integrally with the base, thecentrally located pedestals being oonnected with each other by'integrally cast walls and forming with said walls the lower casing andthe upper edge o'l' all pedestals and of the lower casing being arrangedin one horizontal plane.

An additional object ot the invention is to provide an attrition millthe pedestals and bearing shells whereof have cooperating means :toraligning the bearings on the base.

Another object ot the invention is to provide an attrition mill, thefeeder shoe whereof forms at the same time the housing for one ot thecentrally located bearings, this bearing can be arranged as near aspossible to the working mill head. By thus shortening the length ofshatting between the bearing and said mill head vibratory movement otthe shatt eliminated as `far as possible.

@ther objects ot the invention not specilica-lly mentioned may be easilyascertained and understood from the following description in connectionwith the accompanying drawings forming a part thereof. lt is, however,to be understood that the invention is not to be limited or restrictedto the exact constructions or 'formations shown in the drawings anddescribed in the specification, but that said invention is only to belimited by the scope ot the claims appended hereto.

iln the drawings illustrating some prel'erred embodiments of theinvention:

Fig. 1 is longitudinal vertical section through the attrition millaccording to the invention. Y

Fig. 2 is mill.

Fig. 3 is an end view of a casing ot a bearing lor the milling shafts ofsaid mill.

Fig. et is an end view ont the base ot said mill.

Fig. 5 is a vertical cross section of the mill taken on line 5 5 ot Fig.1.

Fig. 6 is a-cross section on line G--G of Fig. 1.

Fig. 7 is a vertical longitudinal section through the Jfeeder shoe.

Fig. Sis a view similar to Fig. 7 but of a slightly modified torni.

The base 10 is cast in one piece and the head pedestal 11, the feederpedestal 1Q, the center pedestal 13, and the tail end pedestal 14 arecast integrally with said base. rllhe base of an attrition mill has tosustain the greatest strain right between the two centrally locatedpedestals i. e., between. the feeder; pedestal and the center pedestalwhere the actual work of the milling is done. ln order to strengthen thebase at this place walls 13 are provided connecting the two centralpedestals, and forming at the saine time the lower casing. rlhe top atop view ot the base ot said surfaces ot all pedestals and oit the sidewalls 13a of the lower easing are loe-ated on the same level, so thatthese surfaces may be machined siumltaneously. These surlfaces arearranged at such height, that they are located approximately in 'thesame horizontal plane with the axes of the milling shalits. Through thisarrangement it becomes easier to close the casing tightly and inaddition to that the machining of the upper casing is facilitated.

(ln the head pedestal 11 the head bearing 15 is supported. The centerpedestal 13 carries the center bearing 1G and the tail end pedestal 111the tail end bearing 17.

The feeder pedestal 12 supports the feeder shoe 18. This shoe iforms, aswill be described later, the housing for the teeder shoe bearing 18a.Alignment ledges 19, are cut into the top supporting surfaces of theditferent pedestals. Since, as stated above, these surfaces are alllocated in the same `horizontal plane, said alignment ledges can all beout simultaneously. The housing of each of the milling shaft hearings,ineluding the feeder shoe, which forms the housing for the feeder shoebearing 18a, has a pair of supporting wings or arms 21 which areprovided with shoulders 20 co-operating with the ledges 19 to align thehousings of the bearings and the feeder shoe on the base of the mill. Bymeans of the shoulder 2O on the supporting arms 21 it is possible tobore all the housings and the feeder shoe on the same jig, so that thesebores will be properly aligned when the parts are assembled on the baseof the mill. The lower or supporting'surfaee of the arms 21 of thedifferent housings and of the feeder shoe are arranged approximately inthe same horizontal plane as the axis of the bore of each housing, sothat the top surface of each pedestal will be positioned approximatelyat the same height with the axes of the milling shafts, after the millis assembled. The indicated location of the supporting arms 21 on thehousings of the bearings makes it possible for the bearings to hang inthe pedestals instead of to stand thereon.

In addition to the alignment ledges 19 all the pedestals may be providedwith an alignment groove 21a cut into the lowermost portion of thesupporting surface of each pedestal and extending axially over theentire length of each pedestal. If desired the alignment ledges may beomitted and the alignment grooves yonly may. be provided.

If such alignment grooves are provided each of the housings of thebearings 15, 16 and 17 and the feeder shoe 18 is provided with acorresponding key 22, as indicated in Fig. 8, to co-operate with saidgrooves.

The feeder shoe is illust-rated in' Figs. 1, 5, 7 and' 8. In the firstthree gures a preferred embodiment of said feeder shoe is shown, whilethe last named figure represents a somewhat modified form. In thepreferred form the feeder shoe is cast in one integral piece, while inthe modification, said member consists of a plurality of pieces.

The feeder passage 22 is formed by and is located between thefeeder shoeshell 23 and the feeder shoe proper 24. In the preferred form'the feedershoe proper is cast in one piece, while in the modification illustratedin Fig. 8 it consists of the two members 24a and 24h. In each case thefeeder shoe has .a hollowed 'out space 25 adapted to receive the bearing18a, so that, as stated above, the feeder shoe forms the housing forsaid bearing* The lower or bottom portion 26 of the feeder shoe is ofsemi-cylindrical shape. From the hollowed out space 25 a central bore 27leads through the feeder shoe 'to permit the head mill shaft 272ltoextend therethrough. A cover 28 is fastened to the head end of thefeeder shoe in any eonvens S ient manner for instance by means of bolts29u. In the modification of Fig. S these bolts may also hold the parts24a and 2l" together. The material to be treated slides over the feedershoe proper, which is of conical shape. To facilitate the feeding of the1naterial the feeder shoe is provided at both sides with inclined slidesurfaces extending laterally to the inner walls of the feeder shoehousing. The material being fed into t-he mill has the tendency tofollow the ro` tary movement of the open milling head 29, and theinclined surfaces serve in addition to the purpose already mentioned, toprevent said material from such rotary movement, which would bedetrimental to a proper feeding action. On the open milling head 29c afemale seal ring 29d is provided and the feeder shoes housing has afunnel shaped prolongation 29b forming a male seal ring co-operatingwith the ring 291. It is, however, to be noted that the male seal ringmay be made as a separate piece and may be fastened in any convenientmanner to the feeder shoe shell.

By locating the feeder shoe bearing inside i the feeder shoe, thedistance between the bearing and the end of the milling shaft 27a towhich the open mill head 2S) is fastened is reduced to the smallestpossible minimum, so that the vibrations of said shaft caused by theworking action of the mill head are also reduced as far as possible. Inolder mills these vibrations had to be taken care of by using shafts andhearings of comparatively big diameters and by reinforcing the mill headwith a-.heavy hub. These heavy parts do not only cost more than thelighter ones adapted to be used in connection with the presentinvention, but took up more space, so that the area of the feederpassage was reduced as compared with the present construction.

As shown in Fig. 1 the housings of the bearings 15, 16, and 17 consisteach of a body 30, 31, and 32 respectively. rlhe lubri cant for thebearing will be introduced, as indicated, on the end of the bearingopposite the cover. Through this arrangement the lubricant will beforced through the bearing toward the cover, so that when it is desiredto remove the used grease, it is only necessary to take off the cover,and the old, dirty and stale grease can be taken out easily.

It has been customary to provide air slots in the end walls of thefeeder shoe housing. In the present construction air slots 36 areprovided in the side walls. This arrangement prevents any dust, dirt,etc., escaping through said slots from falling near the place where theshaft penetrates the feeder shoe.

On top of the feeder shoe shell and the feeder shoe, the feeder housing37 is arranged. Adjacent the upper end of said housing a drive shaft 38is journalled. Outside of the housing on the end of said shaft extendingtoward the head end of the mill a pulley 39 is rigidly mounted. A belt40 (Fig. 5) may be trained over the head milling shaft 27 and saidpulley to drive the latter. On the opposite end of the drive shaft 38 asmall spur gear 4l is rigidly mounted outside the feeder housing.Underneath the drive shaft 38 a driven shaft i3 is journalled in thefeeder housing and on one of its ends an internal spur gear 44: isrigidly mounted outside of the feeder housing and meshes with the smallspur gear 4l.

Feeder blades l5 are rigidly mounted on the driven shaft inside thefeeder housing. 'I'he internal gear forms, so to say, a protectivecasing for the gear transmission of the feeder and these gears are alsoprotected by being arranged between the feeder housing and the uppercasing of t-he milling heads.

On top of the feeder housing the feeder hopper 4G is fastened.

rIhe head shaft 27a may be driven in any suitable and convenient manner.In the drawings a pulley 47 is shown on the shaft, and this pulley maybe driven by a belt (not shown) from a motor or the like.

Vllhe tail shaft 48 is supported by the center bearing 18 and the tailbearing 17. This shaft may be driven also in any convenient and suitablemanner, for instance by means of a drive pulley 49 as indicated in Fig.l. This figure also illustrates the device for holding the tail shaft inworking position in relation to the head shaft, and for permitting saidtail shaft being moved axially away from said head shaft, if a stone orany other hard substance should happen to enter between the millingheads.

Fig. 6 shows the device permitting axial movement of lthe handwheel 50in relation to the adjustment device but securing said wheel againstrelative rotary movement. Since said devices are of well knownconstruction and do not constitute a part of the present invention theyare not described in detail.

Having described my invention and how the same is to be performed Iclaim as new and desire to secure by Letters Patent:

1. In a device of the class described, a base having a head and a tailend, a plurality of pedestals on the head end, a plurality of pedestalson the tail end, said pedestals being integral with said base and ofequal height, a bearing supported on each of said pedestals, means onsaid pedestals for aligning said bearings, means on said bearings forcooperating with said first mentioned means, a milling shaft journalledin the bear ings on the head end, a second milling shaft journalled inthe bearings on the tail end, milling heads arranged on the ends of saidshafts adjacent to each other, a feeder shoe having a feeder canalending adjacent said milling head, said shoe being supported by one ofthe pedestals on the head end and adjacent the mill head, and said shoebeing adapted to receive and support one of said bearings, and a feedermechanism on said feeder shoe.

2. In a device of the class described a base having a head and a tailend, a plurality of pedestals on the head end, a plurality of pedestalson the tail end, said pedestals being integral with the base and ofequal height, the two centrally located pedestals being connected byintegrally cast walls, a bearing on each ofsaid pedestals, a millingshaft journalled in the bearings on the head end, a second milling shaftjournalle'd in the bearings on the tail end, milling heads arranged onthe adjacent ends of t-he milling shafts, a feeder shoe on the pedestalon the head adjacent the milling head, a feeder mechanism supported bysaid feeder shoe, means on said pedestals for aligning said bearings,means on saidbearings and said feeder shoe for co-opeiating with saidfirst mentioned means, and a housing for one of said bearings formed byand in said feeder shoe. V

In witness whereof I affix my signature.

AUGUST SCHUCHARDT.

